Device for producing rectilinear movement of the optical assembly in cinematograph apparatus



May 31, 1949. A BECOTE 2,471,715

DEVICE FOR PRODUCING RECTILINEAR MOVEMENT 0E THE OPTICAL ASSEMBLY 1N CINEMATOGRAPH APPARATUS Filed Aug. 7, 1947 2 Sheets-Sheet l vl V @www :I

INVENTQR /vo/Ms fcarf AGENTS May 31, 1949. A. BECOTE 2,471,715

DEVICE FOR PRODUCING RECTILINEAR MOVEMENT OF THE OPTICAL ASSEMBLY IN CINEMATOGRAPH APPARATUS Filed Aug. 7, 1947 2 Sheets-Sheet 2 l lNvEN-VOR A Nro/NE 5560 TE BYMMIM@ AGENTS Patente-d May 31, 1949 UNITED STATES PATENT FFICE Antoine Bcote, St. Etienne, France Application August 7, 1947, Serial No. 767,233 In France December 18, 1941 Section 1, Public Law 690, August 8, 1946 Patent expires December 18, 1961 Claims. 1

This invention relates to means for producing rectilinear movement of the optical assembly in cinematograph apparatus.

In such apparatus it has already been proposed to obtain a quick alternating movement of the objective as suggested in French Patent No. 800,375 of January 6, 1936, in which there is described an arrangement of a cam control with two rollers and two interposed controls with a retracting spring, but in use and in order to give more smoothness to the movement it appears necessary to design a device with twin cams actin-lr alternately to produce rectilinear motion of the optical assembly in cinematograph projection apparatus with continuous unwinding of the lm.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which- Figure 1 is a front elevation partly in section of the device with twin cams.

Figure 2 is a sectional side view corresponding to Figure 1 of the device with twin cams.

Figure 3 is an outside plan view corresponding to Figure 1.

Figure 4 is a diagrammatic view of the two twin cams.

Referring to the drawings, two twin cams A--A of appropriate and similar cross-sectional shape are coupled together on the same drive shaft B, but are arranged to act alternately in the following manner. The cam A starts from the high point to the low point of the initial travel and the other cam A' from the low point to the high point, this being to effect the movement of the optical system or objective C which is enclosed in a collar C secured to the movable cage E (the reciprocating upward and downward movement of the objective has already been described in French Patent specifications Nos. 760,- '778 of December 6, 1932, and 783,926 of January 9, 1935.

The optical system C is carried by a movable cage E arranged between right hand and left hand uprights or guideways D-D which are secured to the case E mounted on the cinematograph apparatus.

The movable cage E slides between the uprights D-D and in order that it may slide more smoothly, the uprights D-D are each provided with balls F or rollers, or ball bearings. The central portion and also the two sides of the movable cage E are hollowed out to enable the two cams A-A' to rotate freely inside, so as to produce the desired movement.

jThe end of the drive shaft B bears ,against a 2 ball bearing B housed in an inner cross-member B secured to the uprghts D-D. On the front face, the uprights D-D are connected together by a hollow cross-member B".

The connection of the movement between the cams A--A and the movable cage E is as follows:

Two rollers or anti-friction bearings G-G' are mounted, one at the top, the other at the bottom of the movable cage E, each of said rollers G--G' being adapted to bear against and follow the edge of the corresponding cam. The roller G is mounted on a movable guide I-l supported by a plate l secured to the movable cage E, the said roller being maintained in engagement with the edge of the corresponding cam by means of leaf spring J. The arrangement is such as to compensate for any wear or play which may occur during operation and by this means the movable cage E, which is supported at the top and at the ybottom cannot have any reaction and is perfectly guided. The compensation for side play between the cage E and its guideways is effected by means of springs K.

In order to obtain a smoother and more iieX- ible movement and to reduce the inertia of the movable cage E, it may be statically and dynamically balanced by means of helical springs L connected to the base of the movable cage E and to Xed points of attachment M on the case E'. A similar eect may be obtained, if desired, by means of counterweights or by compressing a liquid in a piston or by any other suitable system. It is also possible to produce a vibratory movement by means of springs acting in opposition, i. e. by action and reaction of counterreaction of the movement.

In the arrangements described above the weight of the optical system, and also that of the movable cage E which carries it, is no longer involved and the shifting time can be reduced, thereby enabling the shutter to be eliminated.

The operation of the device is as follows:

When the shaft B carrying the two cams A and A is rotated one revolution, the movement of one cam increases while that of the other decreases. The movable cage E is engaged at the top by vits roller G and the cam A, and the bottom by its roller G and cam A'. The movable cage E is thus locked between them and follows perfectly the reciprocating upward and downward movement between the uprights D-D.

In order to obtain a very smooth movement and Aeliminate vthe friction as indicated, said uplshown with their-diiTerence of` setting and also ,'i

' `to follow'the picture ofthe lm and thentofhave-- f -a quick upward movement, the shifting time' when f the optical system takes up the next picture.: The

Y ongthe v periphery ofthe slopes ofthe cams vAWA',

3 rights D are provided with balls and the roller G at the bottom of the movable cage E is mounted on a guide so that it can slide freely.

The engagement of the roller G with the edge `4 portion of which bears against the movable cage for urging it in a predetermined direction and helical springs connecting the frame with points of the movable cage for urging it vertically in the of the cam A-is obtained by means'of the-.spring 5 ..oppositedirection blades J, this being in order to absorb Ithe impact or reaction of the movement and. also to compensate for play or wear which might occur.

3. lnv a'kinematographic: apparatus of the continuous lm unwinding type, the provision of an optical system and means for producing a re- Springs K are also provided-,ato takeup any lat-41;.. xciprocat'ing.r rectilinear movement of the latter eral play which might occur.betweenthamcvablev ...comprising arotary shaft, two cams rigid with cage E and the uprights D-Df .In-order to f the shaft the shape and setting of which cams obtain a very flexible movement, theinertia of... is such that the uppermost tangent to one cam the cage is reduced by balancing it statically and the lowermost tangent to the other cam are and dynamically by meansi of helica1= springs L permanentlyspaced by a constant distance for all and a leaf spring N which slides ybetween theV Triangular settings of the shaft, a stationary frame rollers O. frigid with the apparatus and including vertical The diagrammatic view of Figi. Llzof'.theproiile 2n1f.-sli\:leways, a movable Cage Slidingly Carried beof the cams A-A shows that each cam is,formed .tween said slideways and carrying the optical With a very gentle. slope corresponding to the system, two rollers..cooperating respectively with time required by the optical system or objective go the upper and 10Wer end 0f the Cage, means OT securing saidwrollers Ato thecage one-='of which 1 "means-f is rigid' with the -Am'ovabley cage 7and-means for yieldingly connecting the'epthercarrying I means with said movable cage.

` 4. Inca kinematographic apparatus-ofthe con the two rollers-G Gf xed'bo the movable Cage tinuous lm-unwinding type,-the1provision-of an E for controlling same. It should be noted that Optical System and'meansorproducingsa'recipif these-movements were reproducedseveral times" lO'Cang 'rectilinear'mOi/ement'fof thelatter comprising-=a rotaryrshaft, two 'camsrig'id with the orientation-of `the two twin cams AA" is also"v times by-'effecting a rotation of Atheir drive'shaft." All these arrangements apply to `cameras and alsoto lthe *other* systems described inthe afore"' said priorppatents.

such that theuppermost'tangent'toone cam and It will..be understood; that the system hereinbeiore described. maybe ap- Ypliedin various other' applications.

lthelowerrnost'tangent to the .other cam are permanent-ly spacedby afconstant distancehfor all angular settings-of the yshaft;-aistatioriary frame SZ- rigid with the apparatus andl includingvertical #-'slidewaysg -a movable cage -fslidinglyn carried bel. w tween said-slideways andcarrying thefoptical system, leaf springs arranged between-theverti -i #cal-.surfaces of =therframe andthe movable cage le for taking up side play,-rol1ers'rotatably carried lrotating."rectilinear movement ,of .the latter comwat the upper Img and'at @widower-farm of the .I prising, a lrotary shaft, two. cams'` rigid with the Cage and Qperajtlvely"engagmgmrespecmvely the shaft the shape and-settingof.-whichr .cams isiHumm.TALpOrtmn Fof the" first Cam ,and 'the lower such thatfthe uppermost .tangent .to-.one .cam and 4,.. pfjrtln Oghe second cm1?! V `.the.lowermosttangent-.to the..other camare per- '5' n a" 'mematograp lc'appa'ratusofthe con' u .ma'nently spaced by` .a constant ..distance..for all tmuous mm unwnding type the provision an v`...angular settingsoitheshaft,.a stationary, .frame ""Ippmczll systemfandfmeangor :producmg'a recp' yrocatingi vrectilinear:movementaof` the latter comn frigid, with .the..apparatus and. includingvertical f lideways,..a.movable cageslidingly carried be-l cllsalletng ge .nwee` ,.s'd L W-pel' end andat :theflower end of thecage and rigidw'ith im@ apparatus and.'tncl'udmgwertcal .Sperativelyeigsgingirespectively.theupper por-fj"Qgagagg (r rggt trlscolecals. Cam and the lower p muon' of V'wHsystem, tworollers-cooperating respectively with n 2. In a liinematographic4 apparatus .onthe conl 'theAuPpr 31nd lowepnds'of'wthe cagelmeans .for tintuous lri unwinding type,the provision 0f an.' t .,.op ical sys em end means Ifor.phoducing a re`f, 'n 4 .ciprocating. rectilinear. movement-of ,thealatter fm I me "other arrymg ...,comprising a .rotarywshafa ytwo.camsrgid with AgNOINE BCOTE thefshaftthe Shape and setting..of.,which,cams v .issuch that the. uppermost tangent to #one cam andthe .lowermost .tangent to the other cam are l ...permanently spacedbya, constant distance :for 4'55 Y allangular-settings of vthe shaft, a stationary le of uns patent' :.frame rigid with theapparatus andhinoluding iff; UNITED'STATES. :EAIFENTS si xverticalslideways,v la.;movable; cage Sldingly car-,h Number I claim: I 1. Inakinematographic. apparatusoithe con- .,tinu'ous lm unwinding type, the provisionA of an Voptical .system andmeanson` producing .a.reci`p :l le REEERENCES'EEITED The following. references are of recordLin the ried'between said slideways andcarryingiffthe op- 111,317 450, Y lvlole S .gtfelglg tical system; -rollersrota-tably carried: at :the up- -70 177957,93 au Mall l31 1931 fper end and-,at Vthelower endl-'vof fthe: cage and 11914854L-p Hau Jungo 1933 ..:'operatively-;engaging:respectivelyrthe.upper portion of the rst cam and the lower portionof the 1 FOREIGN PATENTS i ;'.-fsecond,c am,;za leaf springitheiends'of which are Number .,--Couniry :jt-.i Date ai: .rslidinglynsecured.cto the -frame and vtheamedial 7511-: '760,7'78l e yFrance ......&';.ac Deuda?, 1933 

